This invention relates to non-aqueous sunscreen compositions having an amount of a volatile silicone oil sufficient to maintain the sun protection factor (SPF) of the compositions at a value greater than about 20.
The sun protection factor (SPF) is a measure of the protection from the sun afforded by a sunscreen agent or composition containing same; compositions having higher SPF values afford more sun protection and are preferred. M. G. deNavarre discloses that small amounts (0.1 to 5 weight percent) of silicone oils can be used in suntan oils to make the oil film formed on the skin more water repellent. See for example The Chemistry and Manufacture of Cosmetics, 2nd Ed., 1975, Vol. III, Chapter 22, pp. 330 and 351 and Vol. IV, Chapter 39, pp. 667 and 668, Continental Press, Orlando, Fla. However, there is no disclosure by deNavarre of any effect silicone oils may have on enhancing the SPF value of the suntan composition. U.S. Patent 4,559,225 (R. G. Fourman) discloses waterproof sunscreen composition having SPF values from 2 to 20. While the sunscreen compositions disclosed by Fourman contain volatile silicon oils, use of a film-forming cellulosic polymer in amounts ranging from 0.10% to 10.0% and a solvent such as an aliphatic alcohol for the cellulosic polymer in the range of 10% to 90.0% of the total composition are required to produce the waterproof sunscreen composition. Westwood Pharmaceutical sells a Presun SPF-29 UV-A/UV-B waterproof sunscreen product. The Westwood Pharmaceutical product is an emulsion product which does not contain any para-aminobenzoates (PABA) UV-B type sunscreening agents. There is still a need for non-emulsion non-aqueous sunscreen composition having a high SPF value, i.e. a value greater than about 20, which may contain a wide range of UV-A and UV-B type (including PABA type) sunscreening agents. There is also a need for non-emulsion non-aqueous waterproof sunscreen composition having a high SPF value.